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Objective: To evaluate the role of the rapid influenza diagnostic test (RIDT) and clinical decision in the diagnosis of H1N1., Methods: In November 2009, 290 suspected influenza patients were examined for H1N1 during an outbreak in Riyadh, Saudi Arabia. Nasopharyngeal swabs were analyzed using Directigen EZ Flu A+B kit. Monoclonal anti-human influenza A/B and reverse transcription- polymerase chain reaction (RT-PCR) were used. Positive and negative controls were used in each run of specimens. Validity indices were calculated for RIDT and clinical diagnostic criteria., Results: The sensitivity and specificity of RIDT were 40.5% (95% confidence interval [CI]: 33.0-48.5), and 94.5% (95% CI: 88.6-97.6). The sensitivity of clinical decision was 66.3% (95% CI: 58.4-73.4), and the specificity was 65.4% (95% CI: 56.3-73.4). The sensitivity of clinical decision was higher in early presenters (79.2%; 95% CI: 57.3-92.1). The RIDT sensitivity was higher in younger patients (48.4%; 95% CI: 35.7-61.3). The positive predictive value (PPV) was 90.4% (95% CI: 80.7-95.7) for RIDT, and 71.1% (95% CI: 63.1-78.0) for clinical decision. The PPV for RIDT was greater for older (94.7%; 95% CI: 80.9-99.1) and late (90.7%; 95% CI: 76.9-97.0) presenters. The adjusted odds ratio for clinical decision was significant for cough, headache, and fatigue., Conclusion: The RIDT can be useful in epidemics and high prevalence areas, whereas clinical decision, and RT-PCR complement the diagnosis of H1N1 in any setting.

Background: Quantitative knowledge of the transmissibility of influenza is crucial to its prevention and control., Objectives: To quantify the transmission of influenza A (H1N1) and seasonal influenza in household contacts of patients with influenza diagnosed in a large university hospital., Patients/methods: A prospective study was conducted between September and October 2009 in which all confirmed cases of influenza diagnosed at King Khalid University Hospital were included. All household contacts were followed by telephone calls every other day for 12 days. They were asked about the development of influenza symptoms in addition to their age and nationality., Results: Overall, 432 household contacts of 69 influenza A (H1N1) cases and 417 contacts of 91 seasonal influenza cases were included. Suspected influenza was diagnosed in 16·9% and 14·4% of household contacts of H1N1 and seasonal influenza patients, respectively. Household reproduction numbers were 1·06 (0·84-1·28) for H1N1 and 0·66 (0·51-0·81) for seasonal influenza. Children in households were more susceptible than were adults (22·2% versus 13·7%, respectively). Evidence of coughing in the index case tripled the risk of infection in households afflicted with the H1N1 influenza [relative risk (RR) = 3·28, CI = 1·24-8·69], while evidence of a runny nose doubled it (RR = 1·89, CI = 1·19-2·92)., Conclusions: Communicability of influenza in households in Riyadh is comparable to that in other countries. Children are more susceptible to influenza infection. The presence of a cough or runny nose in the index cases increases the risk of infection., (© 2011 Blackwell Publishing Ltd.)

Background and Objectives: A new test (Dr. KSU H1N1 RT-PCR kit) was recently developed to provide a less expensive alternative to real-time reverse transcriptase-polymerase chain reaction (RT-PCR). We report the findings of a validation study designed to assess the diagnostic accuracy, including sensitivity and specificity, of the new kit, as compared to real-time RT-PCR., Design and Setting: Cross-sectional validation study conducted from 18-22 November 2009 at a primary care clinic for H1N1 at a tertiary care teaching hospital in Riyadh., Patients and Methods: Nasopharyngeal swab samples and data on socio-demographic characteristics and symptoms were collected from 186 patients. Swab samples were sent to the laboratory for testing with both real-time RT-PCR and the new Dr. KSU H1N1 RT-PCR kit. We measured the sensitivity and specificity of the new test across the entire sample size and investigated how these values were affected by patient socio-demographic characteristics and symptoms., Results: The outcomes of the two tests were highly correlated (kappa=0.85; P<.0001). The sensitivity and specificity of the new test were 99.11% and 83.78%, respectively. The sensitivity of the new test was affected only minimally (96%-100%) by patient characteristics and number of symptoms. On the other hand, the specificity of the new test varied depending on how soon patients were tested after onset of symptoms (100% specificity when swabs were taken on the first day of the symptoms, decreasing to 75% when swabs were taken on or after the third day). The specificity of the new test also increased with increasing body temperature., Conclusion: The new test seems to provide a cost-effective alternative to real-time RT-PCR for diagnosing H1N1 influenza. However, further testing may be needed to verify the efficacy of the test in different settings and communities.

Objective: To determine the meningitis and influenza vaccination coverage rates among Saudi military personnel in Riyadh (Central Military Region [CMR]), Kingdom of Saudi Arabia, (KSA) and the socio-demographic factors that influence vaccination., Methods: This cross-sectional descriptive study was carried out on a sample of 2286 military personnel from different army forces and different military ranks in CMR in KSA selected by a 2-stage stratified random sampling technique. A self-administered questionnaire designed for the National Military Health Survey was used with a section added for assessment of vaccination status. Data collection was carried out from May to August 2009., Results: The response rate was 97.6%. The vaccination coverage was higher for meningitis (51.7%) compared with influenza (17.8%). A high percentage lacked awareness of their vaccination status. Vaccination rates were higher in the Land Forces, and increased with more years of education, and lower crowding index., Conclusion: The proportion of vaccination coverage among military personnel in CMR of KSA is low, especially for influenza, along with their awareness of their vaccination status. A vaccination program that includes awareness promotion of vaccine-preventable diseases is recommended, with changes in the policies to mandate vaccination against meningitis and influenza.

Background and Objectives: A national plan of management for flu-like illnesses was developed by the Saudi Ministry of Health after the first outbreak in Saudi Arabia in June. We describe the clinical presentation of the H1N1 cases attending King Khalid University Hospital (KKUH) between July through September 2009 and identify the high-risk age groups., Methods: All patients presenting with influenza-like illnesses (ILI) in the H1N1 clinics during the specified period were clinically examined and tested using reverse transcription polymerase chain reaction (RT-PCR). Those who were clinically diagnosed and confirmed positive for novel influenza A (H1N1) were included in the study., Results: Over a 6-week period, 117 cases of laboratory-confirmed cases were reported in KKUH with a mean (SD) age of 19.6 (16.7) years, of whom 72 (62.1%) were males. Most reported cases were Saudis (n=99, 85.3%); 94 (81%) had no travel history outside the country; 100 (86.2%) had had no contact with an H1N1-identified patient; 33% were aged 5-14 years and 28.4% were aged 15-29 years. The most commonly reported symptoms were fever in 99 (85.3%), cough in 9 (81%), runny nose (33.6%) and sore throat (21.3%). All 117 cases were confirmed positive using real time RT-PCR testing. Thirty-one cases (26%) were admitted and 22 of those (71%) recovered after receiving oseltamivir. Two deaths were attributed to the 2009 pandemic. One patient died of chronic pulmonary disease. The other cause of death was unknown., Conclusion: These findings indicate indigenous influenza A (H1N1) transmission, and confirm the urgent need for prevention strategies which specifically target children and young adults, who appear to have a higher risk of infection and hospitalization. Such measures include immunization, improved personal hygiene, and increased ventilation in habitations.